A variety of cooling arrangements for reducing rolls in metal strip rolling mills are known in the prior art. The prior art systems are widely varied in complexity and cost of manufacturing and they also vary in effectiveness and operational efficiency. Examples of the known prior art noted herein under 37 C.F.R. 1.56 are shown in the following U.S.Pat. Nos.
______________________________________ 1,335,267 3,648,996 1,384,085 3,684,177 3,400,891 3,766,763 3,510,065 3,779,054 3,514,984 3,784,153 3,570,725 3,877,510 3,587,265 3,880,358 3,589,160 3,905,216 3,606,162 3,990,284 3,629,015 4,081,141 ______________________________________
The objective of the invention is to provide a highly reliable and efficient zoned digitally controlled coolant flow system for the reducing rolls of metal strip mills. The apparatus involved in the invention includes unitized coolant headers which are installed at the most advantageous locations relative to rolls requiring cooling during the reducing of metal strips. Each coolant header carries a required number of valve assembly modules and each such module may carry one or several remotely controllable valves and associated coolant spray nozzles whose aperture sizes in a given module of the apparatus can differ in a fixed area ratio such as 2 to 1, 4 to 1, and 8 to 1. This gradation of nozzle aperture size in the individual coolant zones of the digital system enables a widely changeable coolant flow rate in any or all zones varying between on or off for a single control valve and nozzle to as much as a 15 to 1 flow rate change where four valves and nozzles are present in each module of the apparatus corresponding to each zone requiring cooling. In any chosen array of valves and nozzles per modular unit of the system, selected valves and nozzles are fully on or fully off without analog or gradient control of the coolant flow. This assures within the system that a constant unchanging coolant spray configuration is maintained with a constant full coolant spray impingement force against the face of the roll undergoing controlled cooling in multiple zones.
Where electrically operated coolant control valves are employed, the valve modules are prewired and equipped with individual quick disconnect receptacles. At an appropriate point or points on each coolant header, a further connector for the wiring of multiple modules is provided for coupling to the main control cable extending to the remote push button digital control console or panel. The invention is also compatible with pneumatic or hydraulic valve control means, and pneumatic control tubes for the valves of individual modules can be preassembled in the same spaced provided for wiring.
In the overall, the invention is characterized by simplicity, compactness and rugged durability to withstand the rigors of rolling mill environment. It is designed for ease and economy of maintenance, and on a comparative basis with the prior art is economical to manufacture and install. Most importantly, the invention is thought to possess a flexibility of operation within multiple zones which is beyond the capability of the known prior art.
Various features and advantages of the invention beyond those already mentioned will become apparent during the course of the following description.